Distributed control and navigation system for quadrotor UAVs in GPS-denied environments

The problem of developing distributed control and navigation system for quadrotor UAVs operating in GPS-denied environments is addressed in the paper. Cooperative navigation, marker detection and mapping task solved by a team of multiple unmanned aerial vehicles is chosen as demo example. Developed intelligent control system complies with on 4D\RCS reference model and its implementation is based on ROS framework. Custom implementation of EKF-based map building algorithm is used to solve marker detection and map building task.Comment: Camera-ready as submitted (and accepted) to the 7th IEEE International Conference Intelligent Systems IS'2014, September 24-26, 2014, Warsaw, Polan

Building safer robots: Safety driven control

In recent years there has been a concerted effort to address many of the safety issues associated with physical human-robot interaction (pHRI). However, a number of challenges remain. For personal robots, and those intended to operate in unstructured environments, the problem of safety is compounded. In this paper we argue that traditional system design techniques fail to capture the complexities associated with dynamic environments. We present an overview of our safety-driven control system and its implementation methodology. The methodology builds on traditional functional hazard analysis, with the addition of processes aimed at improving the safety of autonomous personal robots. This will be achieved with the use of a safety system developed during the hazard analysis stage. This safety system, called the safety protection system, will initially be used to verify that safety constraints, identified during hazard analysis, have been implemented appropriately. Subsequently it will serve as a high-level safety enforcer, by governing the actions of the robot and preventing the control layer from performing unsafe operations. To demonstrate the effectiveness of the design, a series of experiments have been conducted using a MobileRobots PeopleBot. Finally, results are presented demonstrating how faults injected into a controller can be consistently identified and handled by the safety protection system. © The Author(s) 2012

Delineation of Criteria for Admission to Step Down in the Mild Traumatic Brain Injury Patient

Patients that suffer a mild traumatic brain injury with intracranial hemorrhage are commonly admitted to an ICU with repeat imaging in 12–24 hours. This is costly to the healthcare system. This study aimed to evaluate this practice and to identify criteria to triage patients to lower levels of monitored care. A retrospective review was performed at a university based level I trauma center. Patients with mild TBI were included. Data was collected on demographics, neurologic status at 6, 12 and 24 hours, CT scan results, and medical or surgical interventions required. 389 patients were evaluated, 53 had a documented neurologic decline while admitted. Factors found to be associated with a neurologic decline included GCS\u3c15 (p=0.002), age greater than 55 (p\u3c0.001), and warfarin use (p=0.039). Aspirin and Plavix were not associated with neurologic decline. No patient age\u3c55 with a GCS of 15 had a documented decline. Several risk factors were found to be associated with neurological decline after mild TBI. These include age\u3e, GCS\u3c15, and warfarin use. Patients age\u3c55 with GCS 15, posed minimal risk for deterioration. Patients age \u3c55 and with a GCS of 15 can be admitted to a monitored step-down bed with less frequent neurologic checks